1、MIL-B-52761 30 7777706 0108558 MIL-B-52761(ME) 11 September 1973 MILITARY SPECIFICATION BELTING, FLAT: CONVEYOR, RUSBEA INDUSTRIAL SYNTHETIC REINFRCEWXlT 10 SCOPE 1.1 Scope. This specification covers rubber textile-reinforced con- veyor belting made for uninterrupted transportation of packaged artic
2、les and bulk materials. Type: A- B- C- D- 1.2 Classification. Conveyor belting shall be of any combination of the following ty-pes and grades as specified (see 6.2): Smooth rubber cover, both sides. Smooth rubber cover on pulley side, stucco or molded finisn cover on carrying side. Friction surface
3、on both sides. Friction surface on pulley side, stucco or molded finisn cover on carrying side. Grade : 210 rated tension (pounds per inc of belt width) 315 rated tension (pounds per incil of belt width) 420 rated tension (pounds per inch of belt width) 525 rated tens-ion (pounds per inch of belt wi
4、dth) 2. APPLICABLE DOCIJ“TS 2.1 Trie following documents ai tine issue in effect on date of invitation for bids or request for proposal Iorrn a part of tnis specification to the extent specified herein: SPECIFICATIONS Federal QQ-s-J. ccc-c-4u7 PPP-B-601 PPP-B-621 - Strapping, Steel, Flat and Seals.
5、- Cloth, BurlaF, Jute (or Kenaf). - Boxes, Wood, Cleated-Plywood. - Boxes, Wood, Railed and Lock-Corner. f FSI: 3030 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-*, MIL-B-52761 30 W 999990b 0108559 6 W ! MIL-B-52761( ME) STANDARDS Federal FED. TES
6、T - Rubber: Sampling and Testing. METHOD STD. No. 601 Military MIL-sm-105 MIL-STD-1s - Sampling Procedures and Tables for Inspection - Marking for SiniFrnent and Storage. by Attributes. (Copies of specif ications and standards required by sxppliers in con- nection witn specific procurement functions
7、 should be obtained from tne procuring activity or as directed by the contracting officer.) 2.2 Other publcations. The following documents form a part O tais specification to tne extent specified nerein. Unless otherwise indicated, tine issue in effect on date of invitation for bids or request for p
8、roposal shall appiy. AMERICAN SOCIETY FOR TESTING AND MATERIALS D378 - Standard Methods of Testing Flat Rubber Belting. (Application for copies should be addressed to the American Society for Testing and Materials, 1910 Race Street, Pailadelpnia, PA 19103.) UNIFORM CLACSIFICATIOI!I COI4MITT3E, AGZWI
9、 Uniform Freight Classification. (Application for copies snould :se addressed to the Uniform ClassiLication Committee, AWN: Tariff Publishing Olficer, Room UO$, 222 Soutn Riverside Plaza, Cnicago, IL 60606.) NATIONAL MOTOR FREIGHT TRAFFIC ASSOCIATION, INCI, AGENT National Motor Freignt Classificatio
10、n. (Application for copies should be addressed to tne American Trucking Associations, Inc. ATIT: Tariff Order Section, 1016 P Street, NW, Wash- ington, Dc 20036.) (Technical society and technlcal association specifications and stand- ards are generally available for reference from libraries. distrib
11、uted among technic groups and using Federal agencies. ) Tney are also t 2 i Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-B-52761 30 W 7779706 O308560 2 W MIL-B- 52761( ME) 3. REQULREMENTS 3.1 Descri tion. Tie flat, rubber, conveyor belting (he
12、reinafter called belt or -5- belting shall consist of a carcass, a top or carrying surface, and a bottom or pulley surface. 3.2 Material. Material shall be as specified herein. Material not specified shall be selected by the supplier and shall be subject to all provisions of this specification. 3.2.
13、1 Rubber. of natural and synthetic. rubber compound. Rubber shall be natural or synthetic or a combination Tne belt top and bottom shall be the same 3.2.2 Fabric. Tie fabric shall be all nylon, all polyester, or a com- bination of nylon and polyester. 3.3 Construction. 3.3.1 Carcass. The elt carcass
14、 shall be one or more plies of fabric tnoroughly impregnated with rubber. 3.3.2 Belt edges. The belt edges shall be cut or rubber covered. Rub- ber covered edges shall be of the same rubber compound as the top and bot- tom. 1 3.3.3 Longitudinal seams. Longitudinal seams shall be at least 4 inches In
15、 addition, each from the edge of the belt and each longitudinal seam shall be at least 12 inches from any other longitudinal seam in te same ply. longitudinal seam shall be at least 4 incnes, laterally, from any longitu- dinal seam in any otner ply. shall be not more than the number specified in taD
16、le I. The number of longitudinal seams in belt plies Table I. Number of longitudinal seams Belt Width Maximum number of Maximum number of Inches longitudinal seams, longitudinal seams, outer ply inner ply Cut edge i0 tnru 48 O 1 over 43 tnru 60 1 2 over 60 thru 72 2 2 LO thru 26 1 1 over 26 tnru 48
17、2 1 over 48 tnru GO 2 2 over 60 thru 72 3 2 Rubber covered edge t 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-527b1 30 777770b 0108561 Y W MIL-B- 52761( ME ) 3.3.4 Transverse sew. Transverse seams shall be at a 45 degree to 75 degree angle
18、to tie belt centerline. There shall be no more than one trans- verse seam per ply per 100 feet of belt, except there shall be no transverse seams in belts of 1 or 2 ply. from all other transverse seam6 by a longitudinal distance of at least 15 feet. Each transverse seam shall be separated 3.3.5 Skim
19、 coats. Each fabric ply shall be separated from aU other fabric plies by a rubber skim coat. be 0.030 inch for 2 ply, 0.015 inch for 3 ply and 0.012 inch for 4 and 5 The minimum skim coat thickness shall Piye 3.4 Dimensions . 3.4.1 Lengths. The minimum length of the belting shall be as specified Whe
20、n specified (see 6.2), plus sufficient additional belting for testing. (see 6.2), length tolerance shall be minus O, plus 2 percent. 3.4.2 Width. Tie belt width shall be as specified (see 6.2 and 6.4). - 3.4.2.1 Width tolerance, rubber covered edge. The tolerance for widths of 24 inches or less shal
21、l be plus or minus 0.25 inch. widths over 24 inches shall. be plus or minus width. The tolerance for 1 percent of belt nominal 3.4.2.2 Widti tolerance, cut edge. The tolerance for widths of 24 inches or less shall be plus or minus 0.125 inch. The tolerance for widths over 24 inches shall be plus or
22、minus 0.5 percent of belt nominal width. 3.5 Typ es and grades. Unless otherwise specified, the physical require- mentc of all belt types and grades shall be in accordance with table II. Wnen specified (see 6.2), tne warp minimum breaking strength shall be in accordance witn table III. 3.5.1 Type A.
23、 Tne belting snall nave a smooth rubber cover on both the pulley side and the carrying side. 0.2), the tnickness of the rubber cover snall be as specified in table II. Unless otherwise specified (see 3.5.2 Type B. The rubber cover on the carrying side of the belting snall have an approved molded or
24、approved stucco surface design. plier shall secure approval of his particular type of surface design on the cover of the belting vhicn he proposes to submit Oy furnisning a sample to the contracting officer. Unless otherwise specified (see 6.2), the thickness of the rubber cover shall be as specizie
25、d in table II. Tne sup Tie pulley side rubber cover shall be smootii. 3.5.3 me C. The belt outer cover shall consist of a friction surface formed by the rubber impregnating cowourid during the frictioning process. 4 t I Provided by IHSNot for ResaleNo reproduction or networking permitted without lic
26、ense from IHS-,-,- MIL-E-5276% 30 H 9999906 L085b2 b MIL-B-52761( ME) 3.5.4 D. The rubber cover on the carrying side shall nave an approved molded or approved stucco surface design. secure approval of the particular type of surface design on the cover of the belting which he proposes to submit by fu
27、rnishing a sample to the con- tracting officer. Tne cover on the pulley side shall be a friction sur- face formed by the rubber impregnating compound during the frictioning process be ELS specified in table II. The supplier shall Unless otherwise specified (see 6.2), the cover thickness shall 3.6 Ma
28、rking. Belting shaU be molded witn the suppliers name or trade mark, the grade of belting and the last two digits of the year of manu- facture repeated at intervals of 50 feet or less. 3.7 Workmanship. its serviceability. The belting shall be free o defects that may impair Table II. Cover and beltin
29、g physical requirements me Method A B C D of test Rubber cover: Tensile strength, carrying side, minimum, 1b.jsq. in. Ultimate elongation, ca-rry- ing side, minimum: Original, percent After aging, percent Thickness, minimum, inch: Carrying side: Overall Thinnest portion Pulley side Equivalent weight
30、 of cover with molded surface design at spectfic gravity of 1, minimum, lb./sq. ft. Warp elongation at rated tension, maximum percent Warp elongation at break, minimum percent Belting: 2000 400 300 o. 060 o. 030 - - 3 10 Warp minimum breaking strengtin, lb. per inch of belt Grade 210 i680 Grade 315
31、2520 Grade 420 33vo Grade 52s rc200 t 2000 400 300 o. ob0 0.030 0.030 0.43 3 10 1560 2520 3350 4200 2ooo 4.4.2.3 400 4.4.2.3 300 4.4.2.4 coo 6000 6000 t Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-B-52761( ME) 44 QUALITY ASSURANCE PROVISIONS
32、4.1 Responsibility for inspection. Unless otherwise specif ied in the Except as otherwise contract or purchase order, tne supplier is responsible for the performance of all inspection requirements as specified herein. specified in tne contract or order, tie supplier may use his own or any other faci
33、lities suitable for the performance of tne inspection requirements specified herein, unless disapproved by tne Government. The Government reserves the right to perform any of tie inspections set Tortn in the speci- fication where such inspections are deemed necessary to assure supplies and services
34、conform to prescribed requirements. 4.1.1 Acceptability criteria. Conveyor belting which conforms to all requirements in sections 3 and 5 of this specification and pass all ex- amination and tests in section 4 of this specification will be considered acceptable by the Government. 4.2 Classification
35、of inspection. Inspection shall be classified as follows : (a) (b) Quality conformance inspection (see 4.3). Inspection of preparation for delivery (see 4.5). 4.3 Quality conformance inspection. 4.3.1 Sampling. 4.3.1.1 Lot. A lot shall consist of all conveyor belting of one type - and grade presente
36、d for delivery at one time. 4.3.1.2 Sampling for examination. Unless otherwise specified (see 6,2), the sample for inspection shall be taken from a lot as described in table I, section 6 of FED. TEST METHOD STD. No. 601. For the purpose of inspection, a uni? snall be one belt. 4.3.1.3 Sampling for t
37、est. Unless otherwlse specified (see 6.2), the sample for test shall be taken from the lot as specified in table IV. the purpose of tests, a test unit shall be a full width of belting equal in area to 3 square feet. For 4.3.2 Examination. Samples selected in accordance with 4.3.1.2 shall be If the n
38、umber of defective units in tie examined in accordance with 4.4.1. sample equals or exceeds the “Rejection Number R“ in table I of section 6 of FED. TEST METHOD STD.No. 001, the lot shall be rejected. 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,
39、-MIL-B-52761 30 W 7797706 01085b5 1 m Table IV. Sampling for test Lot size Sample size Rejection From To (Number of test units) number Yards Yards O 500 501 1,000 1,001 2,000 2,001 3,500 3,501 5,000 5,001 7,000 7,001 io,ooo Ir- 4.3.3 - Tests. Samples selected in accordance witn 4.3.1.3 shall be Fail
40、ure of any test shall be cause for tested as specified in 4.4.2. rejection. 4.4 inspection procedure. 4.4.1 Examination. The belting shall be examined for the following def ec tc : 101. Type not as specified. 102. 103. 104, Workmanship not as specified, Width not as specified (see 4.4,.). Length not
41、 as specified (see 4.4.1.2). 4.4.1.1 Width. Tne width of the belting shall be determined at 50 foot intervals iGordance with method 2121 of FED. TEST METHOD STD. No. 601. 4.4.1.2 Length. The length of the belting snaU De determined in accord- ance with method 24ll of FED, TEST MEZHOD STD. No. 601, u
42、sing either a steel tape graduated to lo inch or less or a lengtn recording device accurate to 116 inch. 4.4.2 Tests. - 4.4.2.1 Thickness, 4.4.2.1.1 Skim coats. A specimen of the belting witin the full crocs- section cut perpendicular to the principal surface of the material shall be examined for th
43、e required skim coat between plies. metnod 2031 of FED. TEST METHOD STD. No. Oi snail be used to determine the correct thickness. Nonconformance to 3.3.5 shall constitute failure of this test. In case of dispute, 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license
44、from IHS-,-,-MIL-B-5 2761( ME) 4.4.2.1.2 Belting. A specimen of the belting witn the full cross-section cut perpendicular to the principal surface of the material shall be examined for tne required thickness. ME;THOD STD. No. 601 chail be used to determine the correct thickness. A thickness that is
45、less than tne belting thickness (less cover) specified in table II plus the cover thickness specified in table II, if applicable, shall constitute failure of this test. In case of dispute, method 2031 of FED. TEST 4.4.2.i.3 Covers. The thickness of rubber coversshall be determined as specified in me
46、thod 2011 or 2031 of FED. TEST METHOD STD. No. 601. in case of dispute will method 2031 be used. Wnen method 2011 is used, the thickness of the cover shall be tine difference between tne reading for the entire specimen, including the cover, and the tnickaess after the cover has been removed. tnis te
47、st. Only Nonconformance to table II shall constitute failure o 4.4.2.2 Equivalent weight of covers witn molded surface design. Tile equivalent weignt of types “B“ and “D“ covers shall be determined by stripping tine rubber cover from a specimen of the belting at least 4 incnes square in area. its sp
48、ecific gravity determined, and the equivalent weight at a specific gravity of 1 calculated as follows: The rubber stripped from the belting shall be weighed, Equivalent weight at specific gravity of 1 = - W S where : W = weight in grams of 4 by 4 inch of rubber specimen; S = specific gravity of 4 by
49、 4 inch 02 rubber specimen; and, Equivalent weignt in pounds per square foot = ! X 0.02 S An equivalent weignt, in pounds per square foot, that is less than 0.43 snaU. constitdte failure of tnis test. 4.4.2.3 Tensile strength and ultimate elongation of cover on carrying side, types A, B, and D. The tensile strength and ultimate elongation of tine rubber cover on tne carrying side of the belting shal